Generative grinding machine



E. W. MILLER GENEBATIVE GRINDING MACHINE Oct. 30, 1945. 7

Filed Dec. 20, 1940 s Sheets-Sheet '1 0t.so,1945. E: w. MILLER 2,388,173 Q GENERATIVE GRINDING- MACHINE i Fild Dec. 20, 1940 s Sheets-Sheet 2 E. w. MILLER GENERATIVE GRINDING MACHINE' Filed Dec. 20, 1940 3 Sheets-Sheet 3 /J/flnm A v7 10 v v +7 I? I W 1 A Manama UNITED- s'm'rzs PATENT OFFICE (harm my Springof Vermont 1' field. Vt, a mutation Appumim mu :0. 1940. m Nq. 310,955

- W W "cum (cum-1a) 1 Theinventtonherefiiacloaedlawl in m. diretlon pf m. an'bwa 3,:

W W w W WW W m m m m WM u m m w W W WEWW WW a m WW WWM MW W WWWWWW WWWWW W W W W mmmm mm w m m .hmmw fi m u mm M m m m mmm m mmfim WW WWW WW W W W W WWMMWWM wfm mmm mmm WWWWWW WMWWWWW machi'ne'ag grinding and m the was I'lgfluatmmentaryaectlonaimlluftol'lmfi, azrind1ngwheel.ltishbeunderstoodthatmch mowlngapartottheindexinzmeamlnthe same umpmaentegl in description is intended to include alent cutter; of spec!!! .aswelemn callydifl'erentcharacbrimcsandtheoparations'perlorqaedbythelruae; 20 taken on H and H respectively!- Hkewlaethemottheterm'searflnthetolhw .8: I I insdeacrlptiontotetheworkpbeeopl'lglfllsaaecflontahenonflne-lkllo! eratedonbythemnchlne.isintendedtom mm] v f generlcanygearshapercutterfsandotbersrflcla m. llandflaretmsmentaryaacflonalvlewn havlngcurvedmrmees 7 all. 'bed'lllnshbflmtalplanewithmfldonior msmartnboutaverflcalulslothnt mumthe

til a abntmm 'lhelnventionlammeparflcularlynlahdto generating machines or the character mmyapplicatloqflledllamhlfl, 1939, Berlal 110.2011). on which Lebtem Patent No;

2257,850weregranted October-.7, 181. Its

specific ingaslmplerandmore paningrotary movement dexingtheworkpleoerto eration on .dtflrent WW W WW WWW eebnflsuous laceotamtmentpi. :Thecgmla .W m W mmm W WWW WW W WWW W WWW WWW m W W WWW WWW W d J W MW WWWWW W W m m WWW W WWWW.

mouhjted on a shaft 85 and coupled thereto by an adjustable coupling which constitutes a novel feature of the present invention and is later de scribed in-detail. Oscillative movement is imparted to the shaft from a motor 33 by a belt and pulley transmission 86, 35, worm and wheel gearing 36, 31, crank disk 38 with adiustable crank 39, adjustable connecting rod to, and armdl said earlier filedpatent. A bracket 42, rising from the table 26, supconnected with the cam; all: as described in my ports the abutment 30 with provision for adjustment, both as to position and as to the incline: tion of its contact face on which the cam 29 acts.

A workspindle 43. is mounted on the carriage by a bearing 44 and dead center 45,. with its axis parallel to that of the shaft 8!. Itis designed to support work pieces of variousdiameters and other dimensions, one of which is represented at 66, and to c r such work pieces back and forth beneath thegrinding wheel while rotating the workpiece at a suitable angular-ratio to cause generation of the prescribed form by the grind- .ing wheel. In the present illustration the forms to be generated are involutecurves.

As thus .far described the'machine is substantially like that shown in my said patent, to which with respect to Figs. 4 and 5, (counterclockwise with respect toFig. 1). 1 Trip 63 is mounted on a pivot 86 carried by stud 65 which occupies, and is adjustably clamped turn of the pawl into engagement with the index reference is made for fuller explanation and for description of certain details not necessary to repeat herein. I will now pass to the features which distinguish the present invention from the prior one and are herein claimed.

die: An arm 61 keyed to the cam shaft 3! 'is coupled by a connecting rod 48 with an arm 49 having a hub 50 rotatably mounted on the work spindle. The distance of the pivot pin 5| by which-arm 41 is coupled to the connecting rod,

of the pivot 52, which couples the connecting rod and arm 49,-from the axis of the work spindle; and the length of the connecting rod between the pivot centers is equal to the distance between the axes of cam shaft and workspindle. Km 49 carries a pivoted pawl 53 having a tooth 54 which First, the means for rotating the work spinplate in an exceedingly brief interval of time after having been disengaged "from the plate. They are located with an overlap sumcient only to cause complete withdrawal of the pawl tooth from the notches of the index plate with minimum clearance. Thus the period during which the pawl remains clear of the index plate is shorter than the time required for the-indexing means to turn the spindle through the angle between adjacent notches of .the index plate.

A lug 68 (Fig; 4) proiects from the inner end of stud 65 adjacentfto the trip in a position such that it serves as a stop for the trip, supporting the latter rigidly inoperative position for withdrawing the pawl from the index plate. But the trip may-turn about its pivot 66 away fromthe lug 68, permitting pin 62 to pass by it, when the pawl is carried in thereturn direction after having been so withdrawn, and reengaged with the disk. "A leaf spring 69 is secured at one fromthe axis of shaft 3i is equal to the distance end to lugbt and its other end bears on a portion of the trip inward from the pivot 64, exerting force'in the direction to hold the trip against the lug, This springi l adapted to yield far enough fits notches in the circumference of'an index plate 55 mounted on.a pulley 58 (Fig. 6) which is keyed to the work spindle. A tension spring 51, connected at one end to the pawl and at the other to an anchorage 58 on the arm 69, forces the pawl to permitdisplacement of the trip by the pin 62 out of the path of the latter when the pawl is car-' ried in the return direction in engagement with the index plate..

Third, rotary feed for the work piece: The surface of the workpiece to be cut by the grinding toward thespindle axis andnormally holds its tooth 54 in full mesh with one or another of the notches in the index plate. Thus angular movements of the cam shaft are transmitted in equal degree to the work spindle.

Second, the means for indexing the "work: The pulley 56 is embf'aced by a'belt 59 which also passes around a pulley 60 driven by aconstantly running motor 6! (later referred to as the indexing motor) supported by. the carriage .21. The

beltslips'when .the pawl 53 is interlocked with .the index plate 55, and so does not rotate the spindle except when the pawl is withdrawn from the index plate. It is then effective to turn the spindle instantly. Such withdrawal'of the pawl is eifected by the engagement of'a pin 62 on the pawl with a trip 63 mounted on the carriage in position to be enaged by the pin 82 whenthe work piece has been rolled clear of the grinding wheel. It may be noted that withdrawing movement of the carriag'e from the grinding wheel is to the left, as

represented in'Figs. 4 and 5, (to-the right with espect to Figs. 1 and 3), and that the arm 49 and work piece are then turned in clockwise rotation wheel is brought into the exact position for cutting, .and may beadvan'ced. from. time to time so as to cause removal of additional material in one 'or'moresuccessive cuts, by altering the angular relationshipbetween the work spindle t8 and the cam 29. This is accomplished by means of the adjustable coupling between the cam and the shaft 3!, previously referred to. The cam is secured to a holder It keyed to a sleeve H which is fitted closely to the shaft 3| but is free to rotate around theshafti Said sleeve carries, in rigid connection, two lateral arms 12, the extremities of which extend parallel to the shaft so as to embrace a yoke 15. presently described. On each arm there is mounted an inwardly directed key I3, here shown as a helical spline or tooth, but 'whichfmayequally' well be a pin of circular cross section at its protruding extremity. Both keys '78 occupy inclined, preferably helical, keyways or grooves 14 (Fig; 12) in the outer faces of those portions of yoke-I5 which are embraced by the extremities of arms 12. Said yoke embraces the outer end of shaft 3! and carries two inwardly directed keys, splines or teeth H, of any suitable formation, located in an axial plane of the shaft substantially at right angles to the'diameter in which the mid length points of the splines. I3 are located. collar I8 3 keyed and clamped on the outer end of shaft t l. which protrudes from sleeve II. in the space embraced by the yoke II,

and has twodiametrlcaliy opposite arms located in said space, in the outer faces of which are keyways or grooves, complemental to said splines and in which the latter are received, extending lengthwise of the shaft.

Yoke It is clamped on the outer end of a rod or stud I, the major part of whichis contained in I coaxial bore in shaft-ii. with freedom to rotate and slide endwise. Separated bushings fitted in the shaft bore provide bearings for supporting the stud. A spring jl, confined between a shoulder 82 on stud ll ahd the inner end of the bore in the shaft. tends to displace the stud outwardly, and holds its outer end against an adjustable abutment I. which is screw threaded through the housing cover N (Fig. 6) and has an external knob by which it may be manually turned. Ad- .iustment of the abutment causes the yoke to be moved along the axis of the shaft, and the corresponding movelnent of the inclined keyways It in the yoke with respect to the keys of the arms 1!, which have no axial movement, causes the yoke to be rotated through an angle of greater or less degree proportional to the extent of its axial movement. Rotation of the yoke is transmitted through the keys I1 and arms I! to the shaft 3i, and from the latter, through arm 4'', connecting rod 48 and arm I to the work spindle.

ascens cam and. the lnclinationsof the abutment and wheel with reference to the path in which the work carriage travels. When the carriage has been retracted toward the abutment far enough to remove the outside circumference of the work piece away from the rim of the grinding wheel, the pin "of the index pawl I8 engages,the trip, previousb adjusted along slot II to the proper point. and disconnects the pawl from the index plate ll. Instantly the belt '9 driven bythe indexing motor ti begins to rotate the work spindle II, and immediately thereafter the pin passes the trip and allows the pawl to reeng se the index plate before the latter has been turned through an angle greater than that between two adiacent notches. Traverses of the carriage forward and back, and indexing of the work at the end of each return traverse, arereto cause cutting to the right depth. Although. in

It will be noted from Fig. 9 that the engaging parts of the keys and keyways are tapered. The keys are clamp'edto the arms, in which they are respectively mounted. by means of bolts 85 and I. which are designed to permit a limited ad- ,iustment of the keys; and abutment screws ll are mounted in bridge plates 88 on the respective arms to bear on the outer ends of the keys and hold them in close sliding contact 'with'the sides of the respective keywa ys.- The adjustment thus provided eliminates backlash and takes up the elects of wear.

It is not essential that the inclined keys and keyways be provided between the arms I2 and the yoke, rather than'between the yoke and the arms this disclosure, the adjustment of the abutment is lected manually. it will be obvious that automatic means may .be provided for the purpose, and' may be operated automatically to impart an increment of angular advancement to the work'after all the teeth have been once rolled across the grinding wheel face. Any number of successive feeding steps may be thus taken, as needed to bring the parts being ground to finished dimensions. r

What I claim and; desire to secure by Letters V Patent is: r

i.- A machine for generating the face curves of gear teeth, gear cutter teeth, and other curved I I surfaces capable of generation by combined movell, or that the keys and keyways between the latter arms and the yoke be parallel to the axis,

rather than inclined. Either pair of keys and keyways may be inclined and the other parallel to the axis, or both pairs may be inclined in equal or unequal degree, and the angles of inclination may he of a degree of angular movement desired to be given to the work spindle in consequence of a given.displacement of theabutment It. The keyways of the two groups mayfbe of opposite hands. or of the same hand with different degrees of inclinaments of rotation and translation, which comprisesa rotating cutting tool mounted inilxed location, a work carriage displaceabie relatively to said cutting tool, a cam rotatably mounted on desired degree. according to the tion, according tothe coarseness 0r fineness of angular adjustment desired;

Neither is it essential that. the arms connected with the shaft and with cam holder respectively be in pairs. A single arm, or more than two arms. of each category may' be employed. and a connector equivalent in, function to the yoke, but possibly different in form and mounted in a different mannenmay be substituted for. the speclilc yoke here shown, all within the scope of'the protection herein claimed.

n will be plaih from the foregoing descriptionthat oscillation of the cam shaft-ll causes the work piece to be tran'slated'and rotated in a manner to cause that part which is to be acted on by the grinding wheel to' roll back and forth .over the cutting faceof the wheel, with-generation of a curve conditioned by the shape of the said carriagean abutment located in thrust receiving engagement with the face of said cam, a work spindle rotatably mounted on the carriage with its axis parallel to that of the cam, a connecting rod, and means comprising pivots coupling said rod to said cam and work spindle at .points'equidistant from both axes and ate distanee from each other equal to the distance between said axes.

2. In a 'machine of the character set forth, a carriage. a cam shaft and a work spindle mounted :rotatably in said'carriage with their axes parallel a cam mounted on said cam shaft,an abutment in thrust receiving engagement with said seal for causing the carriage to be moved translatively when the cam is rotated, a cutting tool having a revolving active portion in position to performa cutting action on awork piece carried by said spindle when the carriage is so moved, arms connectedto the-cam shaft and spindle respectively,

and a connecting rod pivotally connected with both arms; 'said arms, connecting rod, and a straight line perpendicular to and intersecting the axes of the shaft and spindle. constituting a parallelogram.

3. In a curve generating machine, a carriage," a spindle mounted rotatably on said carriage. a

acts, as

said mounted rotatably on said carriage, means tor oscillating said cam about its axis of rotation; an abutment in thrust-receiving engagement with said cam ior causing movement of the carriage, a pawl carrier rotatable about the axis oi the spindle independently oi! the spindle, means for transmitting angular movement from the cam to the pawl carrier, a pawl mounted on the pawl carwith the spindle tending constantly to rotate it in one direction, a pawl carrier movable rotatably about the ams of thespindlaindependently oi rier, and a plate secured to the spindle in detachan abutment in thrust-receiving engagement said cam icrcau'sing movement of the carridge, a pawl carrier rotatable about the axis of the spindle independently of the spindle, means for transmitting angular movement from the cam to the pawl carrier,-a pawl mounted on the pawl carrier, a plate secured to the spindle in detachablyinterlocked connection with said pawl through which angular movement of the pawl carrieris transmitted to the spindle, motive means in non-positive connection with the spindle, tending constantly to rotate it in one direction, and a trip in the path of a portion of the pawl arranged to disengage the pawl from said plate, permitting the spindle to be turned by said motive means.

5. In a generating machine having a movable carriage and a spindle rotatably mounted on said the spindle, a pawl mounted on said carrier having a toothadapted to enter difierent notches of the index plate and normally projecting into one of them, means for oscillating the pawl carrier and-thereby the spindle, and a trip in the path of a part of the pawl arranged to engage such part and disconnectthe pawl from the index plate and permit the spindle to be turned by said motive means, the trip being adjustable about the axis of the spindle and located to be so engaged by the pawl at spoint short of the limit of travel ot the part of the pawl which so engages it. I

8. In a generating machine having a movable carriage and a spindle rotatably mounted onsaid carriage, spindle rotating and indexing means comprising a notched index plate secured to the spindle, motive means in non-positive connec-' tion with the spindle tending constantly to rotate it in one direction, a pawl carrier movable rotatably about the axis of the spindle, independently ofthe spindle, a pawl'mounted on said carrier having a tooth adapted to enter difierent notches of the index plate and normally projecting into one of them, means for oscillating the pawl carrier and thereby the spindle, and a trip in the path of a part of the pawl arranged to engage such part and disconnect the pawl from the index plate and permit the spindle to be turned by said motive means. i I I I 6. Inc. generating machine'having a movable carriage and a spindle rotatably mounted on said carriage, spindle rotating and indexing means comprising a notched index plate secured to the spa dle, motive means in non-positive connection with the spindle'tending constantly to rotate it in one direction, a'pawl carrier movable rotatably about the axis of the spindle; independently of the spindle, a pawl mounted on said carrier having a tooth adapted to enter diflerent notches of the index plate and normally projecting into one of them, means for oscillating the pawl car-- rier and thereby the spindle, and a trip in the path or a part or the pawl arranged to engage such comprising a notched index plate secured to the spindle, motive means in-non-positive connection with the spindle tending constantly to rotate it in one direction, a pawlcarrier movable rotatably about the axis of the spindle, independently of the spindle, a pawl mounted on said carrier having a tooth adapted to enter diflerent notches of the index plate and normallyprojecting into one of them, means for oscillating the pawl carrier and thereby the spindle, and a trip; in the path of a part of the pawl arranged to engage such part and disconnect the pawl from the index plate and permit the spindle to be turned by said motive means, the trip and the part 01' thepawl which engages it being each beveled substantially to an edge and being so arranged that such edge 01' the engagingpart passes over and beyond the edge I 01 the trip when the pawl has been disconnected from the index plate and before it has been carried thereafter through an are around the spinrotate about parallel axes on said carriage, means part and disconnect the pawl from the index Y permitreconnection oi the pawl with the plate before arrival of said part at said limit of travel '7. In a generating machinehaving a movable carriage and a spindle rotatably mounted on said carriage, spindle rotating and indexing means comprising a notched index plate secured to the spindle, motive means in non-posi'ave connection for transmitting rotation from the cam shaft tc 'the spindle, a cam mounted ce-axially with, and

relatively rotatablewith respect to, the cam shaft, an abutment in thrust-receiving engagement with the cam, means for turning the cam 1 back and forth about its axis of rotation whereby to displace the carriage, and a coupling between the cam and cam shaft for transmitting rotation from one to the other, said coupling having provisions for adjustment to alter the angular relationship between the cam and the shaft.

10. A generating machine as set forth in claim (I 9, in which thecoupllng comprises arms connected respectivelywith the cam and with the arms of both the cam and the axis, the splined connection between the yoke and one of said arms having an angular displacement around the axis of the shaft, whereby such axial movement causes a change intthe angular relationship ot the respective arms, and means for I displacing the yoke in the axial direction.

11. A curve generating machine comprising a supporting structure, a carriage mounted for movement onthe supporting structure, a cuttin tool, a, cam abutment, a work spindle adapted to support a'work piece to beacted on by said cutting tool, a cam shalt parallel to said spindles cam mounted coaxially with said camshaft in position to engage said abutment and exert thrust thereupon, said abutment, cutting tool, cam .shait spear-reand spindle being relatively mountedon the supporting structure and carriage in a manner such that thrust xerted by the cam on the abutment causes a relative traverse between the cutting tool and work spindle, means for transmitting 5 rotation from the cam shaft to the spindle, and adjustable means for e' tering the angular relationship between the cam and cam shaft-about their common axis.

12. In a machine of the character described, a shaft, a bar mounted in said shaft for movement cam about its axis of rotation, an abutment in thrust receiving encasement with said cam for causing movement of the carriage when the cam is so oscillated, a pawl carrier rotatable about the axis of the spindle independently of the spindle,.

- means forltransmitting angular movement from the cam to the pawl carrier, a pawl mounted on the pawl carrier, a plate secured to the spindle in detachably interlocked connection with said pawl through which angular movement of the pawl carrier is transmitted to the spindle, and

rotatably and axially with respect thereto, an arm securedto the shaft, a sleeve mounted rotatably on-the shaft. an arm projecting laterally from said sleeve, and a yoke secured to said bar; the yoke having splined connections with both thefaforesaid arms, and ,one of such splined connections being inclined, whereby axial movement of the yoke-causes relative rotation between the shaft and sleeve.

13. The combination of a shaft, a cam mounted on said shaft and rotatable about the axis thereof, an arm connected with said =cam, an arm connected with. the shaft, a yoke supported by the shaft with capacity for relative movement axially thereof, and splined connections between said yoke and both of the before named arms, one of said. splined connections being angularly disposed with respect to said axis.

14. The combination of a sitely extending lateral ar said shaft and arms having inwardly directed splines engaged with-keyways in the outer exshaft having oppotremities of said arms, a sleeve mounted rotatably on said shaft, arms projecting from opposite sides of said sleeve embracing said yoke, splines on the last-named arms entering keyways in the faces of the yoke which'are embraced, by said arms, and means for adjusting the yoke axially of the shaft the splined connection between the pair of said arms being angularly yoke and one disposedwith respect to the shaftaxis.

15. A machine for generating the face curves of gear teeth, gear cutter teeth, and other curved surfaces capable of I generation by combined r the pawl carrier,

means for diseng the pawl from said plate when the carriage arrives at a prescribed point in its travel, whereby to permit indexing of the spindle relatively to the-pawl carrier.

17. Ina curve generating machine, a translatively movable: carriage, a spindle" rotatably mounted on said carriage, a cam mounted rotatably on said carriage, meansfor oscillating said cam about its axis of rotation, an abutment in thrust receiving engagement with said cam for causing movement of the carriage when the cam is so oscillated. a pawl carrier rotatable about the axis ofthe spindle independently of the spindle, means for transmitting angular movement from the cam to the pawl carrier, a pawl mounted on a plate secured to the spindle in detachably interlocked connection with said pawl through whichangula'nmovement of the a yoke embracing engagement of the pawl with the plate after such independent rotation, of the spindle and plate.

movements of rotation and translation, which comprises a rotating cutting tool mounted in fixed location, a work carriage, a work spindle rotatably mounted on the carriage, said carriage being movable back and forth in a path transverse to the axis of said spindle and being located to carry awork piece mounted on the spindle into and out of operative engagement with the" cutting tool, a cam rotatably mounted on the carriage, an abutment located in thrust receiving engagement with the face of said cam, whereby rotation of the cam is eflective to causedis'placement of the carriage in its prescribed path, means for transmitting rotary movement from the cam to the work spindle, whereby to impart to work pieces a rotary component of motion in addition to the translatlve component given by displacement of the carriage, means for indexing the work spindle ably on said carriage, means for oscillating' said on the pawl carrier,

pawl through which pawl carrier istransmitted to the spindle, means means by which relatively to said rotation transmitting means an increment of 18. In a curve generating machine, a translatively movable carriage, a spindle rotatably mounted on said carriage, a cam mounted rotatably on said carriage; means for oscillatingsaid an abutment in y thrust receiving engagement with said cam for,

can about its axis of rotation,

causing'movement of the carriage when the cam .is so oscillated, a pawl carrier rotatable about the axis of the spindle independently of the spindle, "means for transmitting angular movement from the cam to the pawl carrier, a pawl mounted a-plate secured to the spindle in detachably interlocked connection with said angular movement of the for disengaging the pawl from said plate when the carriage arrives-at a prescribed point in its travel, whereby to permit indexing of thespindle relatively to the pawl carrier, and means for eifecting angular displacement betweenthe cam and the angular movement is transmitted therefrom to the pawl carrier, whereby to impart feeding movement to the, spindle. 19. A curve generating machine comprising a carriage mounted. to, move translatively, a spin die and a cam shaft mounted n said carriage rotatably with their axes of .rotation transverse to the path of movement of the carriage, means for transmitting rotation from the cam shaft to the spindle, a cam mounted coaxially with, and relatively rotatable with respect to, the cam shaft. an abutment ment with the cam, means for turning the cam .back and forth about its axis of rotation wherea coupling between pawl from said plate when in thrust receiving engage tation from one to the other, and means for efiecting indexing displacement between said spindle and said rotation transmitting means. i

20. A curve generating machine comprising a carriage mounted to move translatively, a cam shaft rotatably mounted on said carriage with its axistransverse to the path of movement of the carriage, a cam mounted coaxially with said cam shaft and being relatively rotatable with respect thereto, an abutment in thrust receiving engagement with the cam, means for turning the cam back and forth about its axis, whereby to displace the carriage, a coupling between the cam and cam shaft having provisions for adjustment to alter the angular relationship between the cam and the shaft and being operable to transmit rotation from one to the other, a work spindle rotatably mounted on the carriage, an-

index plate secured to said spindle, a pawl carrier mounted to rotate about the axis of the spindle, a pawl mounted on said carrier and arranged to make interlocking engagement with the index plate at any one of a; number of diiierent points, and means for transmitting rotation from the cam shaft to said pawl carrier.

21. In a generating machine, a translatively -movable carriage, a work spindle rotatably mounted on said carriage with its axis transverse to the direction in which the carriage moves, a' cam rotatably mounted on said carriage, a relatively stationary abutment in thrust receiving relation with said cam, means for ex"- fecting simultaneous rotation of the cam about its axis; with thrust exertion against said abut- ,aasairs movable carriage, a work spindle rotatably mounted on said carriage with its axis transverse tothe direction in which the carirage moves, a cam rotatably mounted on said carriage, a rela tively stationary abutment in thrust receiving relation with said cam, means for effecting simultaneous rotation of the cam about its axis. with thrust exertion against said abutment, and translative movement of the carriage, a pawl carrier angularly movable about the axis of the spindle independently of the spindle, an index plate secured to the work spindle, means for transmitting angular movement from the cam v to the pawl carrier.

to said pawl carrier, a pawl mounted on the pawl carrier in connection with said index platefor transmitting angular movement to the spindle, and a trip located across the pathof a portion of the pawl in position to cause disengagement of the pawl from said index plate, whereby to permit indexing rotation of the spindle relatively 23. in a generating machine, a translatively movable carriage. a work spindle rotatably' mounted on said carriage with its axis transverse to the direction in which the carriage moves, a cam rotatably mounted on said carriage, a relatively stationary abutment in thrust receiving relation with said cam, means for effecting simultaneousrotation of the cam about its axis, with thrust exertion against said abutment, and translative movement of the carriage, a pawl carrier angularly movable about the axis of the spindle independently of the spindle, an index plate secured to the pawl carrier means for transmitting angular movement from the cam to said pawl carrier, an indexing motor in rotation transmitting relation to said spindle, a pawl mounted on the pawl carrier normally interlocked with said index plate for causing the plate 1 to rotate with the pawl carrier, and a trip located in the path of a portion of said pawl operable to disengage the pawl from the plate and permit rotation of the spindle by said indexing motor.

EDWARD W. MILLER. 

